Oscillatable tub with flexible blade

ABSTRACT

An oscillatable tub for a washing machine includes at least one flexible blade attached to and oscillatable with the tub for effecting a washing action. The flexibility of the blade enhances the movement of the washing fluid and articles contained therein.

D United States Patent [191 [111 3,736,775 Smith 1 June 5, 1973 54] OSCILLATABLE TUB WITH FLEXIBLE 1,629,762 5 1927 Woodrow ..68/174 BLADE 2,575,691 11 1951 Smith ....68/l74 x 3,285,040 11/1966 Bochan ..68/134 [75] Inventor: Thomas R. Sm1th, Newton, Iowa [73] Assignee: The Maytag Compamy, Newton, Primary Examiner--William 1. Price Iowa Assistant Examiner-Philip R. Coe 22 d; M 9 1972 Attorney-William G. Landwier and Richard L. Ward [21] App]. No.: 233,231 {57] ABSTRACT [52] US. Cl ..68/23, 68/154 An oscillatable tub for a washing machine includes at [51] Int. Cl ..D06f 23/04, D06f 37/14 least one flexible blade attached to and oscillatable [58] Field of Search ..68/134, 154, 174, with the tub f ff ti a hi action The fl i 68/23; 259/75 bility of the blade enhances the movement of the washing fluid and articles contained therein. [56] References Cited UNITED STATES PATENTS 10 Claims, 7 Drawing Figures 1,629,761 5/1927 Woodrow ..68/174 PATENTEDJUN 5 I975 SHEEI 2 UF 2 Faye;

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OSCILLATABLE TUB WITH FLEXIBLE BLADE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to washing machines and more particularly to an oscillatable tub having at least one flexible blade fixed thereto for effecting a washing action within the tub.

2. Description of the Prior Art Frior art has shown oscillatable tubes for washing machines in which at least one blade was fixed to the tub for oscillatory movement therewith to effect a washing action. Initially, the oscillatable tubs were embodied in non-centrifugally operable wringer-type washing machines but were later also shown in a centrifugally operable washing machine as in my U.S. Pat. No. 2,575,691 issued Nov. 20, 1951. The prior art shows an oscillatable tub having either a single blade or a plurality of equally spaced blades; however, all of the blades shown have been rigid. It is noted that there has been little or no commercial use of the oscillatable tub on a significant scale.

There is a continuing search for an improved washing system for a washing machine that is heightened by the introduction of compact washing machines. An essential consideration in the search is that acceptable levels of washing effectiveness must be maintained. The washing effectiveness can be measured in terms of washability, which is an average degree of cleanness as compared to a standard, and should also be measured in terms of uniformity of cleanness as indicated by the deviation from the mean. Uniformity of cleanness is closely related to the turnover and movement of articles within the washing fluid and to tangling of the articles which accompany certain types of agitation.

The commonly used washing system including a large central agitator cannot effectively be used in compact machines where the washing container must be made smaller while the clothes to be washed therein, except as to total load size, remain a constant. Only by reducing the size, fabric thickness, and construction of the articles being washed could the system now commonly in use be as effectively used in a compact washer construction.

Thus there exists a need for a new washing system for washing machines, and especially for compact units. The system as applied to a compact unit should effectively utilize the entire available space within the washing container to obtain adequate movement of fluid and articles washed therein.

SUMMARY OF THE INVENTION It is an object of the instant invention to provide an improved oscillatable tub having at least one flexible blade and being especially useful in a compact washing machine.

It is a further object of the instant invention to provide an oscillatable washing machine tub including at least one blade having a portion flexibly movable relative to a generally vertical plane of the tub during oscillation thereof.

The instant invention achieves these objects in a washing machine including an oscillatable tub having at least one blade fixed thereto and flexibly movable relative to the tub during oscillation thereof for inducing movement of the articles within the washing fluid for achieving an effective washing action.

Operation of the device and further objects and advantages thereof will become evident as the description proceeds and from an examination of the accompanying two pages of drawings.

DESCRIPTION OF THE DRAWINGS The drawings illustrate a preferred embodiment of the invention with similar numerals referring to similar parts throughout the several views, wherein:

FIG. 1 is an overall view of an automatic washer with fragmentary portions removed to show the instant invention embodied therein;

FIG. 2 is a fragmentary section view of an agitating blade as taken generally along lines 2-2 of flG. 1;

FIG. 3 is a generally horizontal transverse section of the tub. comprising a preferred embodiment of the instant invention; and

FIGS. 4 7 are section views similar to FIG. 3 and show alternate placement of blades in the instant invention.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. 1, there is shown an automatic washer including a cabinet structure comprising a base frame 10 supported on a plurality of adjustable legs 11 and in turn supporting a cabinet sidewall 13 and top cover 14. The top cover 14 includes a hinged door panel 15 normally covering a recessed loading opening and further includes an upwardly extending housing 16 for accommodating various control members such as programming means actuatable by the dial l9.

Mounted within the cabinet structure and effectively support by the cabinet structure through the base 10 is a tube assembly 20 nutationally mounted on the base frame 10 by an inverted tripod arrangement including tub braces 21 connected at the lower end to a support member 23 positioned on a central dome of the base frame 10. The tube braces 21 are connected at their upper ends to a generally imperforate liquid container or tub 24. The tub braces 21 are also resiliently connected to the base frame 10 by centering springs 25 which resist and effectively limit rotation of the support member 23 relative to the base frame 10 but permit nutational movement of the tube assembly 20 relative to the base frame 10.

The base frame 10 also supports, through a movable motor mount 26, a reversible drive motor 29 operable in a bi-directional drive system for selectively effecting an agitating operation or a centrifugal extraction operation. The drive system includes a pulley 30 fixed to the output shaft of the motor 29 and drivingly engaged with a main drive belt 31 which is in turn drivingly engaged with the main drive pulley 33.

The main drive pulley 33 is drivingly connected to either the output agitate shaft 34 through the drive shaft 35 and the gearing of the transmission 36 or to the transmission housing 39 through the drive shaft 35 and a clutch within the transmission 36 that couples the drive shaft 35 to the transmission housing 39.

The transmission-housing 39 includes an upper hub 40 extending upwardly through a central opening in the outer tub. A bearing assembly 43, including a resilient portion 44, is mounted onthe transmission hub 40 and engageable with a flange of the outer tub 24. The agitate shaft 34 extends upwardly from and is supported by bearing 46 within the hub 40 for an oscillating operation as'driven by the gearing within the transmission 36.

An externally splined hub 49 is fixed to the upper end of the agitate shaft 34 to receive the internally splined hub 50 of a tub support plate 51. A flange portion 53 of the tub support plate 51 mates with the underside of the bottom wall 54 of the fabric basket or perforate inner tub 55 through a gasket member 56. The tub 55 is fixed to the support plate 51 with a plurality of bolts 59. A seal assembly 57 is disposed between the tub support plate 51 and the tub flange 45. The outer tub 55 is effectively imperforate to retain washing fluid received from conventional fluid supply means (not shown).

The inner tub 55 is nested within the outer tub 24 and is selectively oscillatable and centrifugally rotatable within the outer tub 24 by the connection to the drive system through the tub support plate 51. The inner tub 55 is perforated for circulation of washing liquid contained by the outer tub 24 during tub oscillation and for permittingcentrifugal extraction. The inner tub 55 is generally aligned with the loading opening in the top cover 14 for permitting the operator to place fabrics within the inner tub 55 and to remove them upon completion of the cycle.

The inner tub 55 defines a washing chamber in which the articles being washed are free to move with and in washing liquid. Movement of the liquid and articles being washed is induced by at least one agitating blade 60 disposed within the washing chamber and fixed to the inner tub 55 for movement therewith. The inner tub also includes a central dome 58 that extends into the washing chamber to accommodate the tub support plate 51.

The construction and mounting of the inner tub 55 permits the tub to be driven for selectively effecting an agitating or centrifugal extraction operation. Operation of the motor 29 in a first direction effects oscillation of the tub 55 by a drive path including the main drive pulley 33, the drive shaft 35, gearing of the transmission 36, the output shaft 34, and the tub support plate' 51. In the opposite motor direction as previously indicated, a clutch arrangement effectively locks the drive shaft 35 to the transmission housing 39 so that the main drive pulley 33 rotates the drive shaft 35, transmission housing 3%, and output shaft 34 as a unit. The inner tub 55 is thus rotated at a relatively high speed for centrifuging washing liquid from the inner tub 55 and articles contained therein.

The nutational support of the tub assembly and the selective operation of the drive system for oscillation or centrifugal rotation is more clearly shown and described in the following patents, each of which are assigned to the assignee of the instant invention: Burkland U.S. Reissue Pat. No. 25,157; Scott et al. U.S. Pat. No. 2,854,297; and Goodlaxson U.S. Pat. No. 3,013,645.

Referring to FIGS. 1 and 2 the blade 60, formed of a flexible material such as polypropylene, includes a lower, relatively thicker, portion 61 connected to the inner tub 55 along the bottom wall 54 and corner radium 63 with a plurality of screws 62. The blades could also be formed integrally with the tub if the tub were molded of a suitable material. An upper portion 64 having an edge bead 65 is disposed in a generally vertical plane extending into the washing chamber and is detached from the tub sidewall 66 beginning at point 67 for flexible movement relative to the tub 55 during oscillatory movement thereof. The web portion of the blade that is surrounded by the lower portion 61 and the edge bead 65 has a decreasing thickness in the upward direction for gradually increasing flexibility above the points of attachment to the tub side and bottom walls 66 and 54.

The flexible agitating blades 60 include the upwardly extending portion 64 detached from the tub sidewall 66 for flexible movement during tub agitation. It is believed that the side-to-side movement from a generally vertical plane of the upper blade tip, as generally shown by broken lines 69 and 70 in FIG. 2, tends to enhance the agitation action and improve the movement of articles within the washing fluid through a fishtail effect.

The fishtail effect is evident at the ends of the stroke where the end of the blade 60 is flexed in one direction relative to the normal position of the blade such as indicated by the broken line 70 in FIG. 2 as the blade moves to the left. The tip of the blade 60 moves relatively quickly from the broken line position 70 to the other position 69 as the direction of blade movement is reversed. This fishtailing provides an improved fluid action adjacent the tip and, in addition, the tip of the blade moves in a direction to produce a physical upward nudge to the articles engaging the tip of the blade 60 as the blade assumes full length at the unflexed position.

Furthermore, the flexibility of the agitating blades 60 absorbs the shock produced at the ends of the stroke as especially present with large loads and provides a less severe engagement with the fabrics to avoid unnecessary fabric wear A further improvement in the washing action is achieved by providing a pair of blades 60 in the washing chamber that are cooperatively close to one another as to produce an accumulative effect on the washing fluid and articles being washed therein. In order to be cooperatively close to one another they must, of course, be significantly less than 180 apart, such as a practical maximum of approximately 135 for example, in order to form a channel therebetween. They must not, therefore, be too close, with an approximate 45 spacing being an effective minimum. The preferred embodiment of the instant invention, as in FIG. 3, includes this feature.

The relatively narrow space or channel between the blades must accommodate fluid and also accommodate fabrics which are moving with an within the fluid responsive to the pumping forces of the blades 60 and responsive to the centrifugal effect of fluid moving generally outwardly and then upwardly in-the space between the blades 60.

The net result of oscillation of the blades and the back and forth flexing of the blade tip is an upward force on the articles and the washing fluid adjacent the blades so that there is a generally upward circulation of the washing fluid and fabrics at the agitator blades 60 as indicated by the arrows 7K in FIG. 1. The overall circulation pattern at other locations in the tub 55 is dependent upon the number and spacing of the agitating blades 60.

As previously indicated, the preferred embodiment as to the number and spacing of blades is shown in FIG. 3. In this embodiment two blades 60 are spaced approximately apart. With this spacing the blades effectively function co-operatively to achieve outstanding turnover of the articles being washed. The upward movement induced at each of the agitating blades 60 and in the space therebetween is cumulative so that the articles move up at the blades, across the top portion of the body of liquid, and then down the other side, generally opposite the blades, and across the lower portion of the body of liquid to complete the cycle.

The positioning of a pair of blades 60 as in FIG. 3, so that the pair is effectively positioned asymmetrically within the tub or eccentrically relative to the axis, is specially advantageous in compact washing machines. The eccentric positioning of the blades 60 leaves the major portion of the washing chamber in tub 55 for better fabric movement and turnover. To place an agitator in the center of a compact tub would leave little space for movement of fabrics.

The embodiment including two agitating blades disposed as a cooperative pair of blades eccentrically to the axis is also disclosed and is claimed in a copending application entitled Oscillatable Tub for Washing Machine filed on an even date with this application by Thomas R. Smith and assigned to the assignee of the instant invention.

In a specific construction of the preferred embodiment of FIGS. 1, 2 and 3 the following structural and operating details were present:

tub 55 inside diameter inches height 14 inches (to water line) lower comer radius 2 inches blade 60 two blades spaced 90 apart material polypropylene thickness 0.156 inches at the edge bead and the base of the flexible portion and tapering to 0.080 inches for an inner web portion at the top thickness of lower portion 61 0.437 inches height 5 inches width 1-9/16 inches at top to 2-% inches at base of flexible portion to 4-3/16 at connection to tub drive stroke 204 speed 54 strokes/minute Referring to FIG. 4, an alternate embodiment including a tub 75 with a single blade 60 is shown. Oscillation of the tub 75 produces good agitation and fabric movement with somewhat less distinctive turnover as compared to FIG. 3.

FIGS. 5, 6 and 7 show still further embodiments of flexible blades 60 in oscillatable tubs 76, 77 and 78. such symmetrical or equally spaced arrangements of two or more flexible blades produce a tendency for upward movement of the fluid and fabrics at the blades 60 and generally downward movement adjacent the center of the tub 55. The turnover, though less visually pronounced, combines with washing in situ to produce acceptable washability under the above operating conditions.

As the speed of oscillation is increased and the length of the stroke is decreased in FIGS. 5, 6 and 7, for example, the turnover is diminished and at relatively high speeds, such as a 90 stroke at approximately 100 strokes per minute, little turnover is observed and the washing is generally effected in situ. The action nevertheless produces acceptable washability results.

it is thus clear that the oscillatable tub of the instant invention, including at least one flexibly movable agitating blade, represents an improved tub construction for a washing machine. The oscillatable tub provides an improved agitating means especially effective in compact washing machines.

In the drawings and specification, there has been set forth a preferred embodiment of the invention and, although specific terms are employed, these are used in a generic and descriptive sense only and not for purposes of limitation. Changes in form and the proportion of parts as well as the substitution of equivalents are contemplated as circumstances may suggest or render expedient without departing from the spirit or scope of the invention as defined in the following claims.

I claim:

1. In a washing machine, the combination comprising: supporting structure means; a tub defining a washing chamber for containing fabrics and supported by said supporting structure means for oscillation about a generally vertical axis; at least one flexible blade having a first portion attached to said tub, said blade including a section portion connected to and extending from said first portion into said washing chamber at a position radially spaced from said axis and detached from a portion of said tub for flexible movement relative to said tub; means for providing washing fluid to said tub; and means for oscillating said tub to effect the washing of fabrics therein through the tub oscillation and blade flexure.

2. In a washing machine as defined in claim. 1 wherein said flexible blade is disposed in a generally vertical plane with said tub in a generally stationary posture.

3. In a washing machine as defined in claim 1 wherein a plurality of flexible blades are disposed in said tub and equally spaced about said vertical axis.

4. In a washing machine as defined in claim 1 wherein said tub includes a sidewall having perforations permitting fluid flow therethrough while retaining the fabrics in said tub and wherein said washing machine further includes an imperforate outer tub in which the perforate tub is contained whereby said perforate tub effectively contains the fabrics being washed and said outer tub effectively contains the washing fluid in which said fabrics are washed.

5. In a washing machine, the combination compris ing: supporting structure means; a tub including a peripheral sidewall and defining a washing chamber for containing fabrics, said tub being supported by said supporting structure means for oscillation about a generally vertical axis; at least one flexible blade attached along a lower portion thereof to said tub at a position adjacent to said sidewall, said blade being detached along an upper portion thereof from said sidewall whereby said upper portion is flexibly movable relative to said tub; means for providing washing fluid to said tub; and means for oscillating said tub to effect the washing of fabrics therein through the oscillation of said tub and the flexure of said blade.

6. In a washing machine as defined in claim 5 wherein the effective flexibility of said blade gradually increases from said lower portion to said upper portion whereby the upper portion effects a fishtail action during oscillation of said tub.

7. In a washing machine as defined in claim 5 wherein a plurality of flexible blades are disposed in said tub and equally spaced about said vertical axis for effecting a generally upward movement of fluid and fabrics adjacent the peripheral sidewall.

8. In a washing machine as defined in claim and further including means for rotating said tub to effect centrifugal extraction of washing fluid from the fabrics being washed therein.

9. In a washing machine, the combination comprising: supporting structure means; a non-rotatable imperforate outer tub supported by said supporting structure means; a perforate inner tub including a peripheral sidewall and defining a washing chamber for fabrics, said inner tub being rotatably and oscillatably supported within said outer tub on a generally vertical axis; at least one flexible blade disposed in said washing chamber and attached along a lower portion thereof to said inner tub at a position radially spaced from Hilld axis, saidblade being detached along an upper portion thereof from said sidewall whereby said upper portion is flexibly movable relative to said inner tub during 0scillation thereof; means for providing washing fluid to said inner tub; means for oscillating said inner tub to effect the washing of fabrics therein through the oscillation of said inner tub and the flexure of said blade; and means for rotating said inner tub to centrifugally remove washing fluid from said fabrics.

10. In a washing machine as defined in claim 9 wherein said means for oscillating is operable for moving said inner tub and said blade through an arc of approximately 204 at the rate of 54 strokes per minute. I

' UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,736,775 Dated June 1973'- Inventor (s) Thomas R. Smith It is certified that error appears in the above-identified patent and that said Letters Patentare hereby corrected as shown below:

Col. 2, line 34 "support" should be supported Col. 2, line 39 "tube" should be tub d Col. 2, line 45 "tube" should be tub Col. 3, lines 62 & 63 "radium" should be radius Col. 4, line 49 I "an" should be and Col. 5, line 53 uch" should be Such Claim 1, line 23 Q "section" should be second-- Signed and sealed this 29th day of October 1974.-

(SEAL) Attest: v p

McCOY M. GIBSON JR. c. MARSHALL DANN Attesting Qfficer 1 Commissioner of Patents FORM PO-1050 (10-69) V uscoMM-Dc scan- 69 r: us GOVERNMENTPRIINTING OFFICE I90 o-ascs-au. 

1. In a washing machine, the combination comprising: supporting structure means; a tub defining a washing chamber for containing fabrics and supported by said supporting structure means for oscillation about a generally vertical axis; at least one flexible blade having a first portion attached to said tub, said blade including a section portion connected to and extending from said first portion into said washing chamber at a position radially spaced from said axis and detached from a portion of said tub for flexible movement relative to said tub; means for providing washing fluid to said tub; and means for oscillating said tub to effect the washing of fabrics therein through the tub oscillation and blade flexure.
 2. In a washing machine as defined in claim 1 wherein said flexible blade is disposed in a generally vertical plane with said tub in a generally stationary posture.
 3. In a washing machine as defined in claim 1 wherein a plurality of flexible blades are disposed in said tub and equally spaced about said vertical axis.
 4. In a washing machine as defined in claim 1 wherein said tub includes a sidewall having perforations permitting fluid flow therethrough while retaining the fabrics in said tub and wherein said washing machine further includes an imperforate outer tub in which the perforate tub is contained whereby said perforate tub effectively contains the fabrics being washed and said outer tub effectively contains the washing fluid in which said fabrics are washed.
 5. In a washing machine, the combination comprising: supporting structure means; a tub including a peripheral sidewall and defining a washing chamber for containing fabrics, said tub being supported by said supporting structure means for oscillation about a generally vertical axis; at least one flexible blade attached along a lower portion thereof to said tub at a position adjacent to said sIdewall, said blade being detached along an upper portion thereof from said sidewall whereby said upper portion is flexibly movable relative to said tub; means for providing washing fluid to said tub; and means for oscillating said tub to effect the washing of fabrics therein through the oscillation of said tub and the flexure of said blade.
 6. In a washing machine as defined in claim 5 wherein the effective flexibility of said blade gradually increases from said lower portion to said upper portion whereby the upper portion effects a fishtail action during oscillation of said tub.
 7. In a washing machine as defined in claim 5 wherein a plurality of flexible blades are disposed in said tub and equally spaced about said vertical axis for effecting a generally upward movement of fluid and fabrics adjacent the peripheral sidewall.
 8. In a washing machine as defined in claim 5 and further including means for rotating said tub to effect centrifugal extraction of washing fluid from the fabrics being washed therein.
 9. In a washing machine, the combination comprising: supporting structure means; a non-rotatable imperforate outer tub supported by said supporting structure means; a perforate inner tub including a peripheral sidewall and defining a washing chamber for fabrics, said inner tub being rotatably and oscillatably supported within said outer tub on a generally vertical axis; at least one flexible blade disposed in said washing chamber and attached along a lower portion thereof to said inner tub at a position radially spaced from said axis, said blade being detached along an upper portion thereof from said sidewall whereby said upper portion is flexibly movable relative to said inner tub during oscillation thereof; means for providing washing fluid to said inner tub; means for oscillating said inner tub to effect the washing of fabrics therein through the oscillation of said inner tub and the flexure of said blade; and means for rotating said inner tub to centrifugally remove washing fluid from said fabrics.
 10. In a washing machine as defined in claim 9 wherein said means for oscillating is operable for moving said inner tub and said blade through an arc of approximately 204* at the rate of 54 strokes per minute. 